We describe the case of a teenager with a structurally normal heart that presented with torsades de pointes and cardiac arrest. He had a history of epilepsy in childhood, mild cognitive impairment and cognitive visual dysfunction. The baseline electrocardiogram had prominent J waves and a marked early repolarization pattern in all the leads, with normal QT interval. We discuss the differential diagnosis for this interesting case, as well as the patient's management.info:eu-repo/semantics/publishedVersio

Anjo, D.

Loureiro, M.

Pinheiro-Vieira, A.

Rodrigues, P.

Roque, C.

Sousa, M.

Torres, S.

Álvares, S.

Oxford Medical Case Reports

PubMed

Patrícia Rodrigues

António Pinheiro-Vieira

Marília Loureiro

Sílvia Álvares

Diana Anjo

Carla Roque

Maria João Sousa

Severo Torres

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A good excuse for skipping the test: electrical storm in a teenager

Repositório Científico da Unidade Local de Saúde de Santo António

Oxford Medical Case Reports, 2016;12, 292–294doi: 10.1093/omcr/omw086Case ReportC A S E R E PORTA good excuse for skipping the test: electrical storm ina teenagerPatrícia Rodrigues1,*, António Pinheiro-Vieira1, Marília Loureiro2,Sílvia Álvares2, Diana Anjo1, Carla Roque1, Maria João Sousa1 andSevero Torres11Department of Cardiology, Centro Hospitalar do Porto, and 2Department of Pediatric Cardiology, CentroHospitalar do Porto, Porto, Portugal*Correspondence address. Department of Cardiology, Centro Hospitalar do Porto, Hospital Santo António, Largo Professor Abel Salazar, 4099-001 Porto,Portugal. Tel: (+351)916309981; Fax: (+351)220900637; E-mail: pfdrodrigues@gmail.comAbstractWe describe the case of a teenager with a structurally normal heart that presented with torsades de pointes and cardiacarrest. He had a history of epilepsy in childhood, mild cognitive impairment and cognitive visual dysfunction. The baselineelectrocardiogram had prominent J waves and a marked early repolarization pattern in all the leads, with normal QTinterval. We discuss the differential diagnosis for this interesting case, as well as the patient’s management.CASE REPORTA 16-year-old male came to the emergency department afterlosing consciousness while taking a test in school. He had abrief prodromal period of dizziness and while he was uncon-scious he had involuntary movements, suggestive of a tonic-clonic seizure.He had febrile seizures and parieto-occipital epilepsy inchildhood, without recent seizures and no medication for overa year. He also had mild cognitive impairment and cognitivevisual dysfunction. Family history was unremarkable.While he was being examined, he had another syncope,with spontaneous recovery. Neurology was called, but a cardi-ologist that was passing by felt that his pulse was quite irregu-lar and suggested an electrocardiogram (ECG).The ECG (Fig. 1) showed sinus rhythm, J wave in all leads,normal QT interval and frequent monomorphic premature ven-tricular complexes (PVCs), with right bundle block morphology.The patient was put on telemetry and immediately afterthat he had several episodes of frequent PVCs, followed by apolymorphic ventricular tachycardia (VT), torsades de pointes(TdP) and ventricular ﬁbrillation (VF) (Fig. 1) requiring a total ofsix successful deﬁbrillation shocks within the following hour.After intravenous magnesium, potassium and labetalol infu-sion, there was a progressive decrease in PVC frequency andthe J wave decreased.Physical examination was unremarkable and body temperaturewas normal. Laboratorial investigations, including baseline electro-lytes, acid-base analysis, thyroid function tests and drug screening,were negative, except for a small decrease in free carnitine and aslight increase in alanine levels (non-signiﬁcant). Lactate and pyru-vate levels were normal; the immune study and screening formetabolic diseases were also negative. Echocardiogram, cardiacmagnetic resonance and cerebral magnetic resonance (includinghypophysis assessment) were normal. No arrhythmias were seenduring a treadmill stress test.Received: August 14, 2016. Revised: September 15, 2016. Accepted: October 2, 2016© The Author 2016. Published by Oxford University Press.This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited.For commercial re-use, please contact journals.permissions@oup.com292Differential diagnosis comprehended the following conditions:(i) Mitochondrial cytopathy—considering the combination ofepilepsy, visual changes, mild cognitive impairment, lowcarnitine and high piruvate levels. However, the clinicalcourse would be quite unusual and genetic testing did notshow any pathologic mutations usually present in thesediseases.(ii) Idiopathic VT/ﬁbrillation—namely, the short-coupled vari-ant of TdP [1], which is initiated by a short couplingFigure 1: In the upper part of the picture, baseline ECG shows sinus rhythm, exuberant widespread J waves, inverted T waves in II and aVF and biphasic in V6, normalQT interval and frequent monomorphic PVCs, with right bundle block morphology; in the bottom part of the picture, the telemetry tracing is seen, with frequent ven-tricular ectopics that degenerated into torsades de pointes.A good excuse for skipping the test | 293interval (<300ms), mimicking the R-on-T phenomenon.However, we found only one described case in which thiscoexisted with J waves [2]. Moreover, he does not exactlymeet the criteria for short-coupled variant of TdP, eventhough he could ﬁt in another form of idiopathic VF ifeverything else is excluded.(iii) J wave syndromes—the fact that this patient has veryprominent J waves (also called Osborn waves) in the infer-ior and lateral leads in the baseline ECG, ﬁtting an exuber-ant early repolarization (ER) pattern, is hard to overlook.Even though ER was usually considered benign, morerecently it has also been associated with cardiac arrest (theso-called Haïssaguerre syndrome) [3].(iv) Catecholaminergic polymorphic VT—the ﬁrst episode hap-pened in a stressful situation, but the blood and urine mea-surements of catecholamines and metanephrines werenormal.(v) A variant of a QT syndrome—mostly because of the occur-rence of TdP, but none of the ECGs showed a markedlyabnormal QT interval.During hospital stay, beta blockers seemed to suppress thePVCs and the patient did not have any other episodes of VT. Animplanted cardiac deﬁbrillator (ICD) was placed for secondary pre-vention and the patient was discharged on bisoprolol 5mg daily.After a few months, he was readmitted after appropriate ICDshocks (and he had several episodes of non-sustained VT previ-ously), while he was resting. A trial of verapamil was done, buthe maintained very frequent ventricular ectopics. Again, he wasgiven intravenous beta blockers, that suppressed the PVCs, andafterwards switched to nadolol tablets (80mg bid).The patient was sent for an electrophysiology study, but atthe time of the study he did not have enough PVCs for perform-ing activation mapping and ablation. Flecainide provocationtest was negative.The results of the genetic study for catecholaminergic poly-morphic VT, QT syndromes and Brugada came back negative.The patient did not have any other signiﬁcant events so far—more than 2 years after the last electrical storm. He is usuallyin sinus bradycardia at rest, without ventricular pacing (pro-grammed at 50 bpm).DISCUSSIONAfter extensive discussion of the case, we concluded that thispatient has idiopathic VF associated with ER. This occurs inyoung adults, usually males, that present with syncope or car-diac arrest, in the absence of structural heart disease or identiﬁ-able channelopathies, without prolonged QT intervals. Etiologyis unknown and they have a poor response to verapamil—noteworthy because verapamil was the ﬁrst line treatmentoriginally proposed for short-coupled variant of TdP (essentiallyindistinguishable from idiopathic VF) [4]. Unfortunately, we donot know exactly how to distinguish ‘arrhythmogenic’ from‘normal’ J waves. However, our patient had markedly abnormalECG features: notched J-point elevation >0.2mV and showing atransient increase, present in all the leads including the infero-lateral, and dowslopping ST segment.This is an entity of which little is known so far, namely itscause or triggering factors. There may be an underlying chan-nelopathy—or more than one—that has not been identiﬁed yet.ICD implantation for secondary prevention is mandatory.Other cases of J wave syndromes have been shown to respondwell to long-term quinidine treatment, and to isoprenalineinfusion in the acute approach of an electrical storm. However,when we observed the patient in the emergency department hewas already in TdP, so we administered drugs used for othercases of torsades (usually associated with long QT). Since we donot have commercially available quinidine and the patientimproved with beta blockers, we pursued this strategy.Finally, this case reminds us that monitoring the heart rateand rhythm during an apparent generalized seizure canunravel surprising arrhythmias. Since this patient also had ahistory of epilepsy, this was a particularly challenging case.CONFLICT OF INTEREST STATEMENTNone declared.FUNDINGNone.ETHICAL APPROVALNo ethical issues posed by the Ethical Committee.CONSENTPatient is now an adult and gave consent for publishing hiscase.GUARANTORDr Patrícia Rodrigues.REFERENCES1. Leenhardt A, Glaser E, Burguera M, Nürnberg M, Maison-Blanche P, Coumel P. Short-coupled variant of torsade depointes. A new electrocardiographic entity in the spectrumof idiopathic ventricular tachyarrhythmias. Circulation 1994;89:206–15.2. Takeuchi T, Sato N, Kawamura Y, Takahashi F, Sato M,Kikuchi K, et al. A case of a short-coupled variant of torsadesde pointes with electrical storm. Pacing Clin Electrophysiol2003;26:632–6.3. Haïssaguerre M, Derval N, Sacher F. Sudden cardiac arrestassociated with early repolarization. N Engl J Med 2008;358:2016–23.4. Rosso R, Adler A, Halkin A, Viskin S. Risk of sudden deathamong young individuals with J waves and early repolariza-tion: putting the evidence into perspective. Heart Rhythm2011;8:923–9.294 | P. Rodrigues et al.

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A good excuse for skipping the test: electrical storm in a teenager

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Repositório Científico da Unidade Local de Saúde de Santo António